Rudder for ship

ABSTRACT

A rudder for a ship, the effective area of which rudder may be varied controllably depending upon the speed of navigation. To this end, the rudder comprises a main rudder portion provided with an auxiliary rudder portion which may be controllably projected rearward of the rudder by hydraulically-operated driving means provided in the main rudder portion.

United States Patent, 1191 Yamamoto Feb. 25, 1975 [54] RUBBER FOR SHIP FOREIGN PATENTS OR APPLICATIONS 1 osami Yamamoto, Tokyo, Japan 1,039,869 9/1958 Germany 114/162 Assignee: Misui and Engineering 1,469,014 12/1965 France 1 14/167 (30. Ltd., Tokyo, Japan P E I T M Br rtmary xammerrygve 11x [221 Sept 1973 Assistant Examiner-Stuart M. Goldstein [2]] App]. No.: 395,987 Attorney, Agent, or Firm-Howson and Howson;

Albert L. Free [52] US. Cl. 114/167 51 1111. c1. B63h 25/06 AB TRACT [58] new of Search 1 14/162 1671 171; A rudder for a ship, the effective area of which rudder 244/91, 87, 42 D, 42 D may be varied controllably depending upon the speed of navigation. To this end, the rudder comprises a [56] References C'ted main rudder portion provided with an auxiliary rudder UNITED STATES PATENTS portion which may be controllablly projected rearward 1,128,508 211915 Quartermaine 114/164 of the rudder y hydraulically-Operated driving means 2,813,689 11/1957 Norton et a]. 114/167 provided in the main rudder portion. 2,908,454 10/1959 DeWolff .1 244/42 DB 3,001,502 9/1961 Stoker 114/167 2 Clalms, 3 Drawing Figure-S l T 1 1 l 1 l 1 l i l I 1 1 1 I l 1 11 [la-Gd RUDDER FOR SHIP The present invention relates to a rudder for a ship and more particularly to a rudder the area of which can be increased controllably.

The conventional rudder is so constructed as to have an area which has a sufficient steering effect in navigation at a normal speed. However, the conventional rudder does not have the desired steering effect at low speed in the narrows or in the harbor. If a rudder having a greater area for the purpose of increase of steering effect in the low speed navigation is provided, there must also be provided a steering arrangement of great power in order to operate such a great rudder. However, such great power of the steering arrangement is in excess in low speed navigation. An object of the present invention is to provide a new and useful rudder system for a ship.

Another object of the present invention is to provide a rudder which is provided with an auxiliary rudder in the rudder blade and which is operated by a proper steering arrangement of relative small power. According to the present invention, the auxiliary rudder may be projected rearward of the rudder in low speed navigation to increase the rudder area to prevent the decrease of steering effect.

Other objects and advantages will become apparent by reference to the drawings and to the following description.

In the drawings,

FIG. 1 is a side view of a rudder in accordance with the present invention;

FIG. 2 is the sectional plan view of a rudder of FIG. 1 with the auxiliary rudder portion retracted; and

FIG. 3 is a sectional plan view showing the rudder of FIG. 1 in a state where the auxiliary rudder is projected or extended with respect with the main rudder portion.

Referring to the drawings, rudder blade 1 has a streamline cross section as shown in FIG. 2 and is reinforced by proper frames 2. The rudder blade 1 is pivoted by pintle 5 to the crown 4 of the stern frame 3 as usual. An auxiliary rudder 7 is slidably provided in the space 6 in the rudder blade 1 and hydraulic cylinders 8 are also provided in the rudder blade, and the piston rod 9 of each hydraulic cylinder 8 is connected to the auxiliary rudder 7. Hydraulic cylinders 8 communicate with a pressurized oil source 10 via a directional control valve 11 through pipes 12 connected by joints 13. The auxiliary rudder 7 is slidably supported by guide surfaces 14 and carried by rollers 15.

In normal navigation, the auxiliary rudder 7 is retracted in the rudder blade 1 (see FIG. 2) and the rudder is the same as a conventional rudder in external form and operation. In order to increase the rudder area, the directional control valve 11 is opened to supply pressurized oil from the pressurized oil source 10 to hydraulic cylinders 8, so that the auxiliary rudder 7 is projected or extended from the rudder blade I as shown in FIG. 3. The auxiliary rudlder is projected to an extent controlled by the supply of pressurized oil to in crease the rudder area, and the supplying of the pres surized oil is automatically regulated according to the speed of ship or manually regulated by operating the valve 11.

From the foregoing, it will be understood that the present invention provides a rudder the effective area of which may be increased during low speed navigation to increase the steering effect and which may be operated by a steering arrangement of small power.

What is claimed is:

1. A vertically-disposed rudder for a ship, comprising a main rudder portion having bearing means secured thereto, and an auxiliary rudder portion horizontally and rearwardly extensible from and retractable into said main rudder portion by translational motion on said bearing means to vary the effective rudder area without substantially changing the vertical depth to which said rudder extends, and remotely-controllable positioning means in said main rudder portion for controllably extending and retracting said auxiliary rudder portion translationally with respect to said main rudder portion independently of the speed of the ship carrying said rudder.

2. The rudder of claim 1, in which said main rudder portion is provided with a trackway along which said auxiliary portion is adapted to move translationally during said extending and retracting, and in which said positioning means comprises hydraulic cylinder and piston means within said main rudder portion and hydraulic control lines extending from said hydraulic cylinder and piston means to said ship.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,867,897 DATED 3 February 25, 1975 INVENTOR(S) Osami Yamamoto It is certifi ed that error appears in the ebove-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading before [52] U.S. Cl. the following should be added:

' [30] Foreign Application Priority Data September 8, 1972 Japan 90110/1972 Signed and sealed this 20th. day of May 1975.

(SEAL) Attest:

C MARSHALL DANN RUTH C. MASON Commissioner of Patents At-testing Officer and Trademarks 

1. A vertically-disposed rudder for a ship, comprising a main rudder portion having bearing means secured thereto, and an auxiliary rudder portion horizontally and rearwardly extensible from and retractable into said main rudder portion by translational motion on said bearing means to vary the effective rudder area without substantially changing the vertical depth to which said rudder extends, and remotely-controllable positioning means in said main rudder portion for controllably extending and retracting said auxiliary rudder portion translationally with respect to said main rudder portion independently of the speed of the ship carrying said rudder.
 2. The rudder of claim 1, in which said main rudder portion is provided with a trackway along which said auxiliary portion is adapted to move translationally during said extending and retracting, and in which said positioning means comprises hydraulic cylinder and piston means within said main rudder portion and hydraulic control lines extending from said hydraulic cylinder and piston means to said ship. 